Handle not found errors better

src/main/db.zig

@@ -55,8 +55,9 @@ pub const Database = struct {
         return db;
     }
 
-    pub fn getNote(self: *Database, id: Id, alloc: std.mem.Allocator) !models.Note {
-        return try clone(alloc, self.notes.get(id).?);
+    pub fn getNote(self: *Database, id: Id, alloc: std.mem.Allocator) !?models.Note {
+        const note = self.notes.get(id) orelse return null;
+        return try clone(alloc, note);
     }
 };
 

src/main/main.zig

@@ -28,14 +28,14 @@ const json_options = if (builtin.mode == .Debug)
 };
 
 // Responds to a request with a json value
-fn respondJson(ctx: *http.server.Context, value: anytype, alloc: std.mem.Allocator) !void {
+fn respondJson(ctx: *http.server.Context, status: http.Status, value: anytype, alloc: std.mem.Allocator) !void {
     var headers = http.Headers.init(alloc);
     defer headers.deinit();
 
     // Don't need to free this k/v pair because they aren't dynamically allocated
     try headers.put("Content-Type", "application/json");
 
-    var stream = try ctx.openResponse(&headers, .ok);
+    var stream = try ctx.openResponse(&headers, status);
     defer stream.close();
 
     const writer = stream.writer();
@@ -45,15 +45,15 @@ fn respondJson(ctx: *http.server.Context, value: anytype, alloc: std.mem.Allocat
 }
 
 fn getNote(srv: *RequestServer, ctx: *http.server.Context, args: RouteArgs) !void {
-    const id = args.get("id").?;
-    const note = try srv.db.getNote(id, srv.alloc);
+    const id = args.get("id") orelse return error.NotFound;
+    const note = (try srv.db.getNote(id, srv.alloc)) orelse return error.NotFound;
     defer db.free(srv.alloc, note);
 
-    try respondJson(ctx, note, srv.alloc);
+    try respondJson(ctx, .ok, note, srv.alloc);
 }
 
 fn healthcheck(srv: *RequestServer, ctx: *http.server.Context, _: RouteArgs) !void {
-    try respondJson(ctx, .{ .status = "ok" }, srv.alloc);
+    try respondJson(ctx, .ok, .{ .status = "ok" }, srv.alloc);
 }
 
 const RequestServer = struct {
@@ -79,7 +79,10 @@ const RequestServer = struct {
             var ctx = srv.accept(alloc) catch unreachable;
             defer ctx.close();
 
-            router.dispatch(self, &ctx, ctx.request.method, ctx.request.path) catch unreachable;
+            router.dispatch(self, &ctx, ctx.request.method, ctx.request.path) catch |err| switch (err) {
+                error.NotFound, error.RouteNotApplicable => respondJson(&ctx, .not_found, .{ .@"error" = "Not Found" }, alloc) catch unreachable,
+                else => unreachable,
+            };
         }
     }
 };